Dixon, on a conference call Thursday afternoon, said he didn't have any concerns over the safety of the temporary street circuit in Houston where Franchitti was involved in a last-lap accident Sunday during the finale of an IndyCar doubleheader that sent Franchitti's car flying into the catchfence.

"He's got control of his phone again," Dixon said. "I've exchanged texts and voice calls with him. He seems to be in good spirits. … It's just sad he won't be my teammate come next weekend to try and finish this out."

Castroneves said on Thursday's conference call that a number of drivers have exchanged emails with Franchitti.

"We joke around a lot," Castroneves said. "A lot of the drivers were sending emails to him, and he didn't answer for awhile because he was on medication. Finally he got his phone back and was able to answer all of us. He's on a lot of medication for the pain. We're very glad. It could have been more serious than that."

Both drivers addressed safety concerns that emerged from Franchitti's crash and a rough, bumpy racing surface on the 1.7-mile street circuit at Reliant Park in Houston.

"I think the track had changed a little bit, either when some drivers had raced on it in '07 (the last time IndyCar raced there)," Dixon said. "I think the biggest issue of the weekend was the frontstretch, and the bumpiness. That wasn't a safety issue. That was an issue that plagued us mostly on Friday. … It was a time crunch to prepare the track."

Castroneves, a three-time Indianapolis 500 winner who is still searching for his first series title, agreed that the course had issues.

"They missed the biggest bump (in Turn 1) before the race, then had to try to repair it," Castroneves said. "You don't need to be a huge expert in racing surfaces to notice that."

Dixon will race with Alex Tagliani, who is filling in for Franchitti, and Charlie Kimball next week for Team Ganassi Racing. Dixon says Franchitti has told him he wants to attend the race and watch but Dixon isn't sure he'll be cleared to make that trip.

Franchitti later tweeted Thursday he was planning to watch the finale on TV.

Franchitti, 40, showed his support for Tagliani, who has won a pole and has a career-best finish of third in four starts at Auto Club Speedway, on Twitter: "@tagliani is the right man for the job, he can win the race in the 10 @Target car and also help @scottdixon9 try to win the championship!!"

Franchitti crashed when he tried to avoid Takuma Sato's car as it bounced off line in Turn 5, a high-speed, sweeping right-hander. Franchitti's car went up over the left rear tire of Sato's car and slammed into a fence, which broke and flew into the crowd.

Franchitti suffered two broken vertebrae, a broken right ankle and a concussion. He had surgery Sunday to temporarily stabilize the ankle and will have a second surgery in Indianapolis.

Fourteen people — 13 fans and an IndyCar official — also were hurt when debris and a piece of the catchfence launched into the stands in Turn 5.

Both drivers indicated the crash could have been much worse. Franchitti's car struck a pole in the fence and spun away from the crowd and back onto the track. His right front wheel, which detached on impact, also bounced away from the crowd.

"I think when we have accidents, it makes you think (about) different areas," Dixon said. "Personally, I didn't think safety-wise (the bumps were) much of an issue."

Race officials and safety workers tended to Franchitti until an ambulance arrived. Team owner Chip Ganassi said when he asked Franchitti how he was before he was put in an ambulance, the driver replied: 'I don't know.'
Juan DeLeon AP